The popular syndicated host, who died Saturday at a charity golf tournament at age 53, also had blocked arteries that probably led to an irregular heartbeat, a Louisiana coroner's office says.

NEW ORLEANS -- A preliminary autopsy found that David "Kidd" Kraddick, the popular host of syndicated radio and TV shows, had an enlarged heart and blocked arteries that probably led to an irregular heartbeat, a Louisiana coroner's office said Monday.

Kraddick, 53, became ill during his Kidd's Kids charity golf tournament Saturday outside New Orleans, then collapsed while being driven to an emergency room, said Granville Morse, a deputy coroner in the Jefferson Parish Coroner's Office. The tournament at Timberlane Country Club raised money to send chronically ill and physically challenged children to Disney World.

Doctors at the nearby Ochsner Medical Center -- a five-minute drive from Timberlane -- "did really just a heroic effort to resuscitate him," Morse said. "They really pulled out the stops. Unfortunately, they couldn't get him back."

He said the autopsy is not final because toxicology tests are not back, but Kraddick's heart was enlarged by cardiac disease, and three coronary arteries ranged from 40 to 80 percent blocked. Those conditions can lead to an irregular heartbeat and collapse, Morse said.

"We can't prove that [is what happened] because he didn't have a cardiac monitor on when he collapsed," Morse said.

Kraddick's program, Kidd Kraddick in the Morning, was based in Dallas and syndicated by YEA Networks to more than 75 Top 40 and Hot AC radio stations nationwide, according to publicist Ladd Biro. He said the radio program is transmitted globally on American Forces Radio Network, and its cast also is seen weeknights on the nationally syndicated TV show Dish Nation.